Martin
Janich1,2, Rolf F. Schulte2, Markus Schwaiger3,
Steffen J. Glaser1
1Department of Chemistry, Technische
Universitt Mnchen, Munich, Germany; 2Imaging Technologies, GE
Global Research, Munich, Germany; 3Institute for Nuclear Medicine,
Technische Universitt Mnchen, Munich, Germany
Broadband
radio-frequency pulses are of great interest for reducing chemical shift
displacements, anomalous J coupling, and increasing spectral selectivity. In
this study broadband refocusing pulses with immunity to B 1
variations are designed using optimal control theory. The pulse design
concentrates on posing least constrains on the optimization. The refocusing
pulse presented here reaches a ratio of pulse bandwidth to peak RF amplitude
of 2.1 and immunity of -10 % to +20 % B 1 variations. The
optimized pulse is compared to a broadband SLR pulse, and validated
experimentally.